Print8.4.1c Stull Stoping
This method is designed for rock masses that are weak but somewhat competent – not as weak to require square sets, but not sufficiently competent to use cut and fill. The method is also conceptually simple. Place timber posts at close intervals to maintain the opening between the hanging wall and footwall. A serious shortcoming of this method is that the close placement of the stulls effectively prevents the use of mechanized equipment. Hand drilling with stoppers, drifters, or sinkers is required; and load is accomplished with labor-intensive approaches such as slushers, small overshot loaders, and so on. Needless to say, as a principal mining method, this one has also disappeared.
However, with this observation, I want you to consider that you could apply this approach to a very small area of a mine, where you had a unique challenge; and it could be a safe and economic solution to whatever your problem is. Instead of timbers, you might use hydraulic jacks. Regardless, there is value in having an awareness of these older but now obsolete mining methods. This reminds me of another very important point. Just because you select a particular mining method, and then successfully use it for a period of time… don’t think you are required to continue using that method if the conditions are changing. As a mining engineer equipped with knowledge of these methods, do not be afraid to change methods if the conditions warrant, or even to modify a method to suit your needs. The need for this, and the opportunity to do so, is most likely to occur in metal deposits.